Modern antidepressant drugs were cleared by the medicines regulator yesterday of causing people to become suicidal, although it acknowledged that better warnings were needed about the real problems experienced by some patients who try to stop taking them.

An 18 month official inquiry into the drugs, which include Prozac and Seroxat, concluded that there was no evidence of increased self-harm and suicidal thoughts in adults - even though last December it found that the drugs made children both suicidal and aggressive. It recommended that young adults aged 18-30 should be carefully monitored while taking them, however, and that nobody should be exceeding the recommended dose.

But the controversy does not seem likely to go away. Both the Royal College of Psychiatrists and the mental health charity Mind said they were concerned that the inquiry had not looked at the full data from clinical trials, but had relied on summaries handed over by the drug companies.

Even while he asserted that antidepressants were safe, Kent Woods, the chief executive of the Medicines and Healthcare Products Regulatory Authority (MHRA) which regulates drugs, said they were being too readily prescribed. Around 19m prescriptions were written for 3.5m people last year. "They have been very widely prescribed and I think it is likely that they will have been over-prescribed," he said.

Guidelines for doctors from the National Institute of Clinical Excellence, also issued yesterday, urged GPs not to prescribe antidepressants of any sort to people with only mild depression unless other treatments, such as talking and problem-solving, fail.

One of the drugs reviewed, venlafaxine or Efexor, made by Wyeth, should only be prescribed by a specialist in mental health because it is associated with more deaths and side-effects.

The concern over the availability of data has been at the heart of the row over this group of antidepressants, known as the SSRIs (selective serotonin reuptake inhibitors). Drug companies have habitually published only the favourable drug trial results.

The MHRA did not learn about the existence of unpublished data showing a suicide problem affecting children on Seroxat, made by the British drug company GlaxoSmithKline, until several years after the trials were finished. GSK is under investigation for allegedly withholding safety data.

While the expert working group convened by the Committee on the Safety of Medicines, which advises the MHRA, asked all the drug companies to supply unpublished trial data on their antidepressants for the review published yesterday, Mr Woods admitted that they did not see the full data, instead relying predominantly upon summaries compiled by the companies.

The Royal College of Psychiatrists told the health select committee, now investigating the pharmaceutical industry's influence, that it is vital that doctors and patients have all the information about a drug. In its statement yesterday it reiterated that position.

"The college considers it is very important that the MHRA has based its report upon both published and un published trials, and has made considerable effort to procure all the unpublished trials held by some of the pharmaceutical industry. We therefore have some concerns that the MHRA has not been able to examine all the evidence upon which this guidance should be based, at least for some of the drugs considered.

"It is also unclear whether there has been an adequate examination of the efficacy of the SSRIs and related newer drugs," it said.

Both the college and Mind welcomed the prescribing guidelines, but Mind's chief executive, Richard Brook, expressed "serious concerns" about the role of the MHRA, which could have taken earlier action as SSRI prescriptions soared and patients complained of side-effects and withdrawal problems.

The Royal College of GPs warned that family doctors faced "a difficult dilemma" in treating people with depression. A spokesman added: "With a chronic shortage of counselling and psychotherapy available on the NHS, GPs often feel that they have little choice but to prescribe anti-depressants in mild to moderate cases. We urgently need more resources in place so patients can be referred for non-drug therapies."